ES2269995T3 - DISPERSIONS CONTAINING BICOMPONENT FLUOROPOLIMERO PARTICLES AND USE OF THE SAME. - Google Patents

Abstract

The present invention provides a method of preparing an aqueous dispersion of poly(perfluorovinyl ether) homopolymers. The present invention further relates to a method of making an aqueous fluoropolymer dispersion comprising bicomponent particles of poly(perfluorovinyl ether) homopolymers and a second fluoropolymer. The dispersions of the present invention may be used for rendering fibrous substrates oil repellent, water repellent and/or stain repellent without altering the looks and feel of the substrate.

Description

Dispersions containing particles fluoropolymer bicomponents and use thereof.

Field of the Invention

The present invention relates to a method of preparation of an aqueous dispersion of homopolymers of poly (perfluorovinyl ether). The present invention relates in addition to a method of preparing an aqueous dispersion of fluoropolymer comprising bicomponent particles of homopolymers of poly (perfluorovinyl ether) and a second fluoropolymer The dispersions of the present invention may be used to make oil repellent fibrous substrates, water repellent and / or stain repellent. The invention is also refers to fibrous substrates, in material particles textiles, treated with the fluorochemical composition and to a method to treat the fibrous substrate with dispersions fluorochemicals

Background

Compositions have been known for a long time to make substrates, particularly fibrous substrates, such as textile materials, oil and water repellent. When treat fibrous substrates and in particular textile materials such as clothing, it is a requirement that the textile material retains its appearance and touch as much as possible. Therefore, the amount of composition that can be applied in any treatment for provide repellent properties to substrates is limited because large quantities would result in an alteration of the appearance and feel of the substrate and would make them little useful for Many applications As a result, the composition used to treating substrates needs to be effective at low levels of application.

It is well known that fluorochemical compounds they are highly effective in providing oil and oil repellency water to substrates and, in particular, to textile substrates. The commercially available fluorochemical compositions can apply at low levels and are generally effective in provide the desired oil and water repellent properties at these low levels.

Fluorochemicals taught to Treat a textile material include polymers based on vinyl ethers which have a perfluoroalkyl group. For example, the US document 4,929,471 describes the use of a copolymer of CH_2 = CH-OR, in which R can represent a fluorinated group to treat a polyester fabric during its process manufacturing so that a polyester fabric is produced that It has physical properties similar to silk or rayon.

US 4,029,867 describes how provide dirt repellent and removal properties from dirt to a textile material using a copolymer of maleic anhydride and a comonomer of the formula CH 2 = CH-CH 2 -O-R f in which R_ {f} represents a perfluorinated group. A homopolymer of CH 2 = CH-O-R f is described in document DE 1720799 and it is mentioned that it is suitable for making an oil and water repellent textile material. The compositions Fluorochemicals mentioned above are all based on fluorine-containing polymers that do not have a main structure fluoridated

Fluoropolymers are known which have a fluorinated main structure such as for example polytetrafluoroethylene (PTFE) and tetrafluoroethylene copolymers (TFE) to coat substrates to provide various properties to the substrate including repellency properties. For example, the fluoropolymers have coated cookware for provide desired removal properties to them. Be describe fluoropolymers having a main structure fluoridated in US 4,546,157, US 4,619,983, US 4,766,190, US 5,110,385, US 5,969,066, US 3,450,684, US 4,035,565, US 4,368,308, US 4,418,186, US 4,654,394, US 4,840,998, US 5,639,838 and US 3,136,745. However, to be effective as a coating repellent, it has been taught how to apply coatings of fluoropolymer in large quantities. However, such thick coatings are unstable to treat materials textiles since they substantially change the look and feel of the textile substrate, ie to the extent that such materials Textiles are unsuitable for use in clothing. Sometimes such coatings are subsequently subjected to a stage of high temperature sintering that would generally destroy many of the fibrous substrates desired for treatment.

EP 969 055 describes a dispersion aqueous containing PTFE and a copolymer of TFE and a perfluorovinyl ether (PVE) for coating substrates such as ceramics or for impregnate a textile material. However, the amount of fluoropolymer in the treatment solution is at least 25% by weight, resulting in a fairly thick coating. In addition, the coating is subjected to a sintering stage to a temperature of 420 ° C that would destroy many fibrous materials Used for clothes.

US 4,670,328 describes dispersions aqueous of certain copolymers of TFE and PVE for the impregnation of textile materials. Again, the level of fluoropolymer applied in the impregnation it is so great that the appearance and touch of the material Textiles are substantially affected. Consequently, the impregnated materials are generally only useful in applications specialized items such as dust-free garments or garments resistant to chemicals in which the appearance of Garments is of secondary consideration.

EP 186186 describes a polymer of curable fluoroolefin to prepare coatings that have properties of high weather resistance and good repellency such as water repellency, oil repellency and / or stain repellency However, apparently a thick coating to achieve these properties.

Fluorochemical compositions for making oil and / or water repellent fibrous substrates are described in the patent application being processed together with the present one of the USSN 09 / 861,782 filed on 5/21/2001. The compositions comprise up to 4% by weight of a fluoropolymer having a fully or partially fluorinated main structure and comprising repeating units of the formula -CF2 -CFR_f -, in which Rf is a perfluorinated organic group that has a chain length of at least two atoms and that has at least one atom of
carbon.

Although perfluorovinyl ether homopolymers have been prepared, and perfluorovinyl ether copolymers have been used in textile treatments, the difficulty in preparing perfluorovinyl ether homopolymers has so far prohibited their use in textile treatments. Therefore, it would be desirable to find alternative fluorochemical compositions that do not have many of the disadvantages of fluorochemical compositions in the prior art. In particular, it would be desirable to find fluorochemical compositions comprising perfluorovinyl ether homopolymers that are effective in providing oil and water repellency to a fibrous substrate, in particular a textile substrate, without adversely affecting substantially the appearance of the textile material, i.e. , such that the fibrous substrate is suitable for use in clothing. Preferably, fluorochemical compositions can also provide dirt repellent and soil removal properties to the fibrous substrate. Desirably, the fluorochemical compositions will be more environmentally friendly and stable enough to substantially prevent the formation of fluorinated substances of low molecular weight. The fluorochemical compositions are also preferably compatible with commonly used textile treatments and are preferably easy to apply by a customer in a reproducible and reliable manner. Finally, the desired fluorochemical compositions may preferably provide lasting repellency properties to a substrate.
fibrous.

Summary of the invention

The present invention provides a method for prepare a homopolymer dispersion of poly (perfluorovinyl ether), which comprises the steps of:

to)

previously emulsify an aqueous mixture of a perfluorovinyl ether in the presence of a fluorochemical emulsifier to a medium size drop of the emulsion of 1 micron or less, and

b)

polymerize said perfluorovinyl ether in the presence of an initiator of free radicals at a temperature and for a sufficient time to produce poly (perfluorovinyl) particles ether).

The perfluorovinyl ether used herein The invention of claim 1 are of the formula: CF_ {2} = CF-R_ {f} in which R_ {f} represents a perfluorinated organic group having a chain length of at minus 2 atoms and that has at least one carbon atom and one atom of oxygen The R f group may be a perfluoroalkoxy group, a perfluoroether group or a perfluoropolyether group.

The present invention further provides a method of preparing a fluoropolymer dispersion that It comprises bicomponent particles, comprising the steps of:

to)

pre-emulsify a mixture aqueous of a perfluorovinyl ether monomer in the presence of a fluorochemical emulsifier up to an average droplet size of the emulsion of 1 micron or less, and

b)

polymerize said perfluorovinyl ether in the presence of a free radical initiator at a temperature and for a sufficient time to produce particles of poly (perfluorovinyl ether),

C)

add at least one additional fluorinated comonomer without fluorochemical emulsifier additional, and

d)

further polymerize the mixture resulting.

As used herein, a "two-component particle" is an individual particle of two different fluoropolymers. The first fluoropolymer is a homopolymer of one or more perfluorovinyl ether monomers. He second fluoropolymer can be any fluoropolymer that comprises one or more fluoromonomers, such as homo or copolymers of tetrafluoroethylene, homo or copolymers of vinylidene fluoride, u homo or copolymers of hexafluoropropylene or homo or copolymers of perfluorovinyl ether. The bicomponent particle may comprise a core-shell morphology, inverted core-deck, crescent or other morphologies

In a further aspect, the present invention provides a dispersion of fluoropolymer to make a substrate fibrous oil and / or water repellent. The fluorochemical dispersion may comprise homopolymer particles of poly (perfluorovinyl ether) or may comprise particles bicomponents of poly (perfluorovinyl ether) homopolymer and a second fluoropolymer as a component.

In a still further aspect, the invention is refers to a fluoropolymer dispersion comprising a two-component particle comprising a first poly (perfluorovinyl ether) and a second fluoropolymer. He first fluoropolymer consists essentially of units of repetition corresponding to the general formula:

\delm{C}{\delm{\para}{R _{f} }}

F ---(I) --- CF_ {2} ---

 \ delm {C} {\ delm {\ para} {R f}} 

F ---

in which R_ {f} represents a perfluorinated organic group having a chain length of at at least two atoms and that has at least one atom of carbon.

It has been found that such dispersions of Bicomponent particles are particularly effective for the Fibrous substrate treatment. In particular, it was found that the second fluoropolymer contributed to an improvement in the properties of repellency that often goes beyond a mere addition of oil repellent properties of fluoropolymers per se themselves, particularly with an auxiliary component, such as describe later. Consequently, the cost of a fluorochemical treatment composition since the cost of the first poly (perfluorovinyl ether) homopolymer is generally superior to that of the second fluoropolymer.

It has been found that the dispersion of fluoropolymer of the present invention is effective in providing oil repellent and / or water repellent properties at a fibrous substrate without substantially affecting its appearance. In addition, fluoropolymer dispersion can occur in such so that the amount of low molecular weight species (less than 1,000 g / mol) in the composition is low, for example not more than 0.5% by weight, preferably not more than 1,000 ppm, or even free of such substances. Also, fluoropolymer dispersions they will generally have high chemical stability such that fluoropolymer dispersions generally do not form substances low molecular weight fluoridates over a long period of time. The fluoropolymer dispersion can also provide repellency. to dirt as well as dirt removal properties or spots With the term removal of dirt and stains you want say that a treated substance that gets dirty or stains can clean more easily, for example, in household washing than a untreated substrate that gets dirty or stains. On the other hand, the dirt / stain repellency refers to the ability to repel dirt, thereby reducing dirt or staining substratum.

The amount of fluoropolymer in a Treatment composition will normally be selected in order to achieve the desired level of fluoropolymer in the substrate that is going to be treated Normally, the amount of fluoropolymer in the Treatment composition is not more than 4% by weight (based on the total weight of the composition), for example between 0.01% by weight and 4% by weight, preferably between 0.05% and 3% by weight. Higher amounts of fluoropolymer can also be used, particularly in cases where the uptake of the composition by the fibrous substrate is low.

In a further aspect, the present invention refers to a treatment of fibrous substrates with the previous fluorochemical compositions. The substrates thus obtained they generally have good repellency properties such as oil repellency, water repellency, dirt repellency. Additionally, the treated substrates can also show good dirt / stain removal or improved properties.

In a still additional aspect of the present invention, substrates are provided, in particular materials textiles, which have been coated on at least part of at least one main surface, with the fluoropolymer dispersion of the invention. The amount of fluoropolymer in such a fibrous substrate Treated should generally be less than 3% by weight based on the weight of the fibrous substrate so that the appearance and touch is preserved general substrate, although the amount that can be applied without adversely affect the appearance and feel of the substrate will depend of the nature of both the substrate as well as the composition Fluorochemistry used in the treatment.

In yet another aspect, the invention relates to use of a fluoropolymer dispersion to confer repellency to oil, water repellency, dirt repellent and / or disposal from dirt / stains to a fibrous substrate without affecting substantially to the appearance and feel of said fibrous substrate, the fluorochemical composition comprising a solution or dispersion of a fluoropolymer having a main structure fully fluoridated and comprising one or more repeat units corresponding to the general formula:

\delm{C}{\delm{\para}{R _{f-} }}

F ---(I) --- CF_ {2} ---

 \ delm {C} {\ delm {\ para} {R f-}} 

F ---

in which R_ {f} represents a perfluorinated organic group having a chain length of at At least 1 oxygen atom and it has at least one carbon atom. By the term "without substantially affecting the appearance and touch of said fibrous substrate "means that the substrate treated does not differ substantially in appearance of the substrate no treated in such a way that the treated substrate can be used without objections in applications such as, for example, clothing, in that the appearance and feel of the fibrous substrate are a consideration main for your use.

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Finally, the invention relates to fluorochemical compositions comprising a dispersion of (of the) fluoropolymer (s) mentioned above and also an auxiliary component, generally an organic compound not fluorinated, which can further improve the properties of water and / or oil repellent and / or dirt / stain removal of a fibrous substrate treated with the fluorochemical composition.

Detailed description of illustrative embodiments of the invention Fluoropolymers for use in the fluorochemical composition

The poly (perfluorovinyl ethers) for your use in the fluorochemical composition are polymers that have a fully fluorinated main structure. The term "totally fluorinated "includes polymers in which all atoms of hydrogen in the main structure have been replaced by fluorine so as polymers in which all the hydrogen atoms in the main structure have been replaced by fluorine and chlorine or bromine.

The fluoropolymer has one or more units of repetition corresponding to the general formula:

\delm{C}{\delm{\para}{R _{f} }}

F ---(I) --- CF_ {2} ---

 \ delm {C} {\ delm {\ para} {R f}} 

F ---

in which R_ {f} represents a perfluorinated organic group (i.e. all hydrogen atoms they have been replaced by fluorine atoms) which has a length of chain of at least one oxygen atom and that includes at least one carbon atom Preferably, the chain length of the group Perfluorinated organic is at least 3 atoms. A group R_ {f} particularly preferred has a chain length of at least 4 carbon atoms of which at least 3 are atoms of carbon.

Examples of R_ {f} groups include groups perfluorinated aliphatics containing one or more oxygen atoms. The group R_ {f}, in particular, can be a group linear or branched perfluoroalkoxy, preferably the group perfluoroalkoxy will have between 1 and 6 carbon atoms and examples specific include methoxy, ethoxy and perfluorinated n-propoxy. Still additionally, the group R_f can be a perfluoropolyether that can be linear or branched. According to a preferred embodiment, the group R f corresponds to the following general formula:

(II) -O (R 1 {} f O) n (R 2 {} f O) m R 3 {} F}

wherein R 1 f, R 2 f each independently represents a group linear or branched perfluoroalkylene having 1, 2, 3, 4, 5 or 6 carbon atoms, R 3 f represents a group linear, branched or cyclic perfluoroalkyl having 1, 2, 3, 4, 5 or 6 carbon atoms and n and m each represents independently an integer from 0 to 10. Preferably, at minus one of n and m is different from 0. R_ {f} groups particularly Preferred according to formula (II) include those in which m is 0, n is 1, R 1 f is -CF 2 CF 2 -, -CF 2 CF (CF 3) -, -CF (CF 3) CF 2 - or CF 2 CF 2 CF 2 - and R 3 f represents a group linear, branched or cyclic perfluoroalkyl having from 1 to 6 carbon atoms A preferred R f group according to formula (II) includes, in particular, a perfluoroalkyl group and those in the that both m and n are 0. Another preferred R_ {f} group according to formula (II) includes, in particular, a perfluoroalkyl group and those in which the sum of m and n is one.

One skilled in the art will understand that the fluoropolymer of the fluorochemical composition may comprise a mixture of repeating units according to formula (I). For example, the fluoropolymer may comprise a mixture of units of repetition in which the R_ {f} groups correspond to the formula (II) above, such as for example a mixture of a unit of repetition corresponding to the formula:

\delm{C}{\delm{\para}{O --- (CF _{2} ) _{2}  --- O
--- CF _{3} }}

F ------ CF_ {2} ---

 \ delm {C} {\ delm {\ para} {O --- (CF2) 2 --- O
--- CF 3 

F ---

and a repeat unit corresponding to the formula:

\delm{C}{\delm{\para}{O --- (CF _{2} ) _{3}  --- O
--- CF _{3} }}

F ------ CF_ {2} ---

 \ delm {C} {\ delm {\ para} {O --- (CF2) 3 --- O
--- CF 3 

F ---

or a mixture of units of repetition derived from a combination of perfluoro (propyl vinyl ether) and a monomer of the formula CF 2 = CF-O-CF 2 CF (CF 3) - O-CF 2 CF 2 CF 3.

The repellency properties that can achieved by fluorochemical composition depend greatly measure of the presence in the fluoropolymer of units of repeat perfluorovinyl ether according to formula (I). It has been found that a fluoropolymer containing only units of repetition according to the general formula (I) produces excellent repellency properties in a fibrous substrate treated with it. Although higher amounts of repeat units of formula (I) will generally improve performance, the cost of fluoropolymer also increases accordingly because the monomers from which these repeating units are derived are generally expensive

In a particular embodiment of the present invention, the fluorochemical composition comprises a dispersion of fluoropolymer comprising bicomponent particles of a first homopolymer of poly (perfluorovinyl ether) and a second fluoropolymer that each have a total main structure or partially fluoridated It is believed that the bicomponent particles are a core-shell polymer comprising a poly (perfluorovinyl ether) homopolymer core and a cover of a second fluoropolymer.

The first fluoropolymer consists essentially in one or more repeating units corresponding to the formula general (I) set forth above. Generally the second fluoropolymer contains the repeating units of formula (I) in a total amount of no more than 50% molar. The number of units repeat in the second fluoropolymer can even be lower, for example no more than 25% molar or not more than 10% molar. In addition, even if less than 1% molar or substantially no repeat unit in the second polymer, beneficial effects of the second polymer have been observed. In particular, it was observed that although generally the second fluoropolymer generally does not provide (for example, if not contains the repeating units of formula (I)) or only up to a Limited degree of repellency properties when used on its own only, the second fluoropolymer can, however, improve the repellency performance when used in a dispersion of bicomponent particles with the first fluoropolymer.

Generally, any reason can be used of the first fluoropolymer with respect to the second to prepare the emulsion and the optimal ratio will depend on the nature of the fluoropolymers used in the mixture, the nature of the substrate fibrous, the amount of mixture applied and the level of repellency wanted. The optimal ratio can easily be determined through routine experimentation Generally, the percentage by weight of First fluoropolymer will be between 1 and 75% by weight, preferably between 25 and 50% by weight, providing the second fluoropolymer the rest. Thus, it has been found that mixtures which are rich in the second fluoropolymer (they have a percentage in weight of the second fluoropolymer of 50% or more), which contains little or no amount of the repeating units of formula (I), They produce good repellency properties. Generally without However, the total number of repeat units according to the formula (I) in such a mixture must be at least 10% by weight, preferably at least 20% by weight, to get good repellency levels

Bicomponent or particle dispersion with core-cover can be prepared by stages from:

1) polymerize an aqueous emulsion of monomers of the formula:

CF 2 = CF-R f,

in which R_ {f} represents a perfluorinated organic group having a chain length of at at least two atoms and that has at least one carbon atom and one atom from oxygen;

in the presence of a free radical initiator and an emulsifier at a temperature and for a sufficient time to produce poly (perfluorovinyl ether) particles,

2) subsequently add at least one comonomer additional fluorinated without additional fluorochemical emulsifier, and

3) further polymerize the mixture resulting.

Preferably, the emulsion of step 1) It comprises drops that have an average droplet size of less than 1 micron, preferably 300 nanometers.

An important benefit of using a mixture of fluoropolymer is that the total cost of the composition of treatment can be reduced while still high performance level, since the cost of the monomers of perfluorovinyl ether significantly exceeds that of the others monomers that can be used in the second phase of the process of polymerization.

The fluoropolymer of the second component of the bicomponent particle comprises a homo or copolymer of at least one ethylenically unsaturated fluoromonomer containing at least one fluorine atom substituent on a carbon atom with double bond, and further substituted with a halogen atom such as fluorine, chlorine or bromine; hydrogen, or a lower fluoroalkyl radical.

Useful fluorinated comonomers of fluoropolymer of the second component include homo and copolymers of tetrafluoroethylene, vinylidene fluoride, hexafluoropropene, chlorotrifluoroethylene, 2-chloropentafluoropropene, 1-hydropentafluoropropene, dichlorodifluoroethylene, trifluoroethylene, 1,1-chlorofluoroethylene, trichlorethylene, and the like and optionally a monomer corresponding to the formula (I) above.

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Generally, the fluoropolymer will contain between 0 and 70% molar, preferably between 0 and 60% molar, plus preferably between 0 and 40 mol% repeating units tetrafluoroethylene derivatives, between 0 and 95% molar, preferably between 20 and 80% molar, more preferably between 30 and 75% molar repeating units derived from vinylidene fluoride, between 0 and 95% molar, preferably between 20 and 80% molar, more preferably between 30 and 75% molar repeating units derived from hexafluoropropene, whereby the total number of repeat units derived from vinylidene fluoride, hexafluoropropene and Tetrafluoroethylene is generally between 0 and 95% molar, preferably between 20 and 90% molar, more preferably between 30 and 90% molar.

The fluoropolymer of the second component of the Fluorochemical composition also contains repeat units derived from non-fluorinated monomers. Examples of monomers no fluoridates include alpha-olefin hydrocarbons such as ethylene and propylene. The amount of such units of Additional repetition may vary widely and may be from 0% molar to 50% molar of any non-fluorinated monomer particular.

Specific examples of fluoropolymers of second component that can be used in the composition Fluorochemicals of this invention are copolymers of tetrafluoroethylene and a perfluorovinyl ether such as perfluoro (methyl vinyl) ether, perfluoro (methoxyethyl) vinyl) ether, perfluoro (propyl vinyl) ether (PPVE-1), perfluoro (2- (n-propoxy) propyl vinyl) ether (PPVE-2) and perfluoro (ethoxy ethyl vinyl) ether, copolymers of tetrafluoroethylene, hexafluoropropylene and a perfluorovinyl ether such as perfluoro (methyl vinyl) ether, perfluoro (methoxyethyl vinyl) ether, PPVE-1, PPVE-2 and perfluoro (ethoxyethyl vinyl) ether, copolymers of vinylidene fluoride and a perfluorovinyl ether such as perfluoro (methyl vinyl) ether, PPVE-1, PPVE-2, perfluoro (methoxyethyl vinyl) ether and perfluoro (ethoxyethyl vinyl) ether, fluoride copolymers of vinylidene, tetrafluoroethylene and a perfluorovinyl ether such as perfluoro (methyl vinyl) ether, perfluoro (methoxyethyl) vinyl) ether, PPVE-1, PPVE-2 and perfluoro (ethoxyethyl vinyl) ether, fluoride copolymers of vinylidene, hexafluoropropylene and a perfluorovinyl ether such as perfluoro (methyl vinyl) ether, PPVE-1, PPVE-2, perfluoro (methoxyethyl vinyl) ether and perfluoro (ethoxyethyl vinyl) ether and fluoride copolymers of vinylidene, tetrafluoroethylene, hexafluoropropylene and a perfluorovinyl ether such as perfluoro (methyl vinyl) ether, PPVE-1, PPVE-2, perfluoro (methoxyethyl vinyl) ether and perfluoro (ethoxyethyl) vinyl) ether.

Preparation method of fluoropolymers

Homopolymer particles of poly (perfluorovinyl ether) are produced through aqueous emulsion polymerization of a previous emulsion that comprises the perfluorovinyl ether monomer and an emulsifier fluorinated in which the average droplet size of the previous emulsion is 1 micron or less, preferably 300 nanometers or less. In the aqueous emulsion polymerization, the monomers are polymerize in the aqueous phase in the presence of an initiator of free radicals and a fluorinated emulsifier, preferably a non-telogenic emulsifier.

Generally the time required for the Homopolymerization is 6 to about 48 hours and the temperatures range from 40 to 80 ° C, preferably from 40 to 60 ° C Higher temperatures can lead to destabilization of the drops.

The fluorochemical emulsifier will be used generally in amounts less than 1% by weight, for example from 0.1 to 1% by weight based on the weight of the phase watery Examples of fluorinated emulsifiers include salts, in Particular linear or branched perfluoroalkyl ammonium salts which contains carboxylic or sulphonic acids that are 4 to 11 carbon atoms in the alkyl chain. Specific examples include perfluoro-octanoic acid ammonium salt (APFO, described in US 2,567,011) C_ {8} F_ {17} SO_ {Li} which is commercially available from Bayer AG, C 4 F 9 SO 3 Li and C 4 F 9 SO 3 K (described in US 2,732,398). An additional example of perfluoroalkyl containing a carboxylic acid salt is C_ {8} F_ {17} SO_ {2} N (C2 {H5}) CH_ {2} COOK (described in US 2,809,990). Emulsifiers yet Additional that may be used include emulsifiers of perfluoropolyether carboxylate such as those described in the EP 219065.

According to an embodiment of the present invention, emulsion polymerization can be carried out using a fluorinated emulsifier having a molecular weight of at least 200 g / mol, preferably at least 1,000 g / mol, for example, using a polymeric fluorinated emulsifier. Examples of high molecular weight emulsifiers or fluorinated polymers Suitable include perfluoropolyethers having one or more groups hydrophilic, particulate ionic groups such as acidic groups carboxylic or salts thereof. Examples of emulsifier of Perfluoropolyether include those according to the following formulas (IV) or (V):

(IV) R_ {f} {a} -O- (CF 2 O) k (CF 2 CF 2 O) p (CF (CF 3) CF 2 O) q -Q 1 -COOM

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(V) MOOC-Q 1 -O- (CF 2 O) k (CF 2 CF 2 O) p (CF (CF 3) CF 2 O) q -Q2 -COOZ

in which k, p and q represent each a value from 0 to 15, usually from 0 to 10 or 12 and the sum of k, p and q such that the average molecular weight is at least 200 g / mol, preferably at least 1,000 g / mol, R f a represents a perfluoroalkyl group of 2 to 4 carbon atoms, M and Z each independently represent hydrogen or a cation, preferably a monovalent cation such as ammonium or an ion of alkali metal and Q1 and Q2 each represent independently -CF_ {2} - or -CF (CF 3) -.

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Examples of fluorinated compounds useful as emulsifiers of formula (IV) include those corresponding to the General Formula:

\hskip4cm

R_{f}{}^{a}-O-(CFXCF_{2}O)_{r}-CFX-COOM

\hskip5cm

(VI)

 \ hskip4cm 

R_ {f} {a} -O- (CFXCF2O) r -CFX-COOM

 \ hskip5cm 

(SAW)

in which R_ {f} a and M have the meanings defined in formula (IV), X is an atom of hydrogen or a fluorine atom and r has a value of 2 to 15. Examples of such fluorinated emulsifiers are described in EP 219065. Commercially available fluorinated compounds according to the formula (IV) or (V) include FLUOROLINK ™ available from Ausimont SpA, KRYTOX? 157 FSL, KRYTOX? 157 FSM and KRYTOX? 157 FSH, all available from E. I. Dupont de Nemours and Company

Polymeric fluorinated compounds still Additional useful as emulsifiers include the perfluoropolymers comprising repeat units that can derive from a monomer of the formula:

one

in which s is 0, 1 or 2, and t is a integer from 2 to 4, and G is a remainder that contains one or more hydrophilic groups, such as a nonionic, anionic or cationic Examples of suitable nonionic groups include: -SO2 F; hydroxyalkylene, for example, - (CH 2) n OH in which n is an integer from 1 to 18; hydroxyarylene; and an ester, for example, -COOR, in which R is an alkyl group of 1 to 3 carbon atoms. Examples of groups Suitable anionics include: carboxyl groups, for example, -CO 2 M, in which M may be hydrogen, a mono metal ion or divalent (for example, sodium, potassium or magnesium), ammonium (for example, simple ammonium, tetraalkylammonium, tetraarylammonium) or phosphonium (for example, tetraalkylphosphonium); or sulfonaate groups, for example, -SO_ {3} M, in which M is defined as above. Examples of suitable cationic groups include groups alkylammonium, (for example, - (CH 2) n NR 3 + Cl - in which R may be hydrogen, alkyl or aryl).

Preferably, the polymeric emulsifier fluorinated is a tetrafluoroethylene copolymer and a monomer according to the formula (VII). Such copolymers and their method of preparation are described, for example, in US 5,608,022 and WO 5/5/2060. Suitable fluorinated polymeric compounds, useful as Emulsifiers are available as superacid catalysts Nafion® (for example, Nafion® SE10172) by E. I. Dupont de Nemours & Co., Wilmington, DE and are also available as polymers Flemion ™ super acids from Asahi Chemical Co., Osaka, Japan and as Acipex ™ super acidic polymers from Asahi Glass Co., Tokyo, Japan.

If desired, several methods can be used to recover and recycle the fluorinated emulsifiers used in the polymerization in aqueous emulsion. Such methods are described, by example, in EP 524585, EP 566974, EP 632009, EP 731081, WO 99/62858, WO 99/62830 and DE 19932771. Any of these methods can be advantageously practiced in this invention to remove and / or minimize any amount of fluorinated emulsifier remaining after emulsion polymerization.

According to a particular embodiment to prepare fluoropolymer dispersions, perfluorovinyl monomer liquid ether used in the polymerization is previously emulsified before homopolymerization. The present method allows the preparation of perfluorovinyl ether homopolymers very much more effective than prior art procedures. Through the term "previously emulsified" in relation to the This invention means that the fluorinated monomer is emulsifies in water to a droplet size of one micron or less, preferably 300 nm or less, with the help of the emulsifier fluorinated before polymerization of the liquid fluorinated monomer. The polymerization temperature to prepare an emulsion of the Perfluorovinyl ether homopolymer is generally between 40 and 100 ° C, preferably between 50 and 80 ° C.

The perfluorovinyl ether monomer can emulsify in water with the help of a fluorinated emulsifier such as described above, before polymerization with the other monomers Prior emulsification of fluorinated monomer Liquid results in an emulsion that has monomer drops. The average droplet size of the previous emulsion can range from a mean diameter of 1 µm or less, up to about 150 nm or less or even lower. Preferably, the average droplet size It is not more than 300 nm. The aqueous emulsion must have preferably an application life (time of sedimentation) of at least 1 hour, more preferably of at least Three hours. Application life or settling time is defined as the time required for 10% by weight of the drops of monomer sediment or separate from the aqueous emulsion. The size of gout can be determined, for example, by experiments of light scattering as known in the art.

Emulsions can be conveniently obtained aqueous perfluorovinyl ether monomer by means of a suitable emulsification such as, for example, mixers of high speed rotor-stator such as a Ultra-Turrax (Ika). Stirring speeds they must be high enough to get the grade desired emulsification and stability. Generally, they can stirring speeds of 24,000 rpm or more are used. Preferably, air is excluded during emulsification. He particle size of the previous emulsion can be reduced additionally with high pressure homogenizers, available from APV Gaulin or Microfluidics.

The amount of fluorinated emulsifier used to emulsifying the liquid fluorinated monomer is generally among the 0.01 and 15% by weight based on the weight of the fluorinated monomer liquid, preferably 0.1 to 4% by weight. Although they can be used higher amounts of emulsifier, will not necessarily lead to a significant increase in the application life of the aqueous emulsion of liquid fluorinated monomer produced. At two-stage procedure to prepare the particle emulsion bicomponents, smaller amounts may be used.

In the two-phase procedure of the present invention, in which a dispersion of particles is prepared bicomponents, first a previous emulsion is polymerized up to a conversion rate of at least 1%, preferably of at least 5%, as described, to produce a dispersion of perfluorovinyl ether homopolymer particles and monomer of Unconverted perfluorovinyl ether (if any). Are added additional fluorinated monomers with continuous stirring while the second polymerization phase advances. The second phase of Polymerization should occur without additional fluorinated emulsifier. In the absence of additional emulsifier, a dispersion of two-component particles and the additional charge of fluorinated monomers polymerizes on the surface of the homopolymer particles of perfluorovinyl ether. In case an emulsifier is added additional fluorinated, a mixture of particles would occur discrete; a first perfluorovinyl homopolymer particle ether and a second fluoropolymer particle derived from the additional fluorinated monomer feed in the second phase of polymerization.

In the two polymerization process phases (to produce the two-component dispersion), polymerization can be started at a first temperature for the first phase of polymerization and a second temperature for the second phase of polymerization. The initial period will normally be between 1 and 6 hours, for example between 1 and 4 hours from the start of the polymerization reaction. If desired, initiator can be added additional during polymerization but this may not be required. The amounts of initiator in the initial charge are generally between 0.01 and 2.0% by weight, preferably between 0.1 and 1.8% by weight, more preferably between 0.3% and 1.6% by weight based on the total weight of polymer to be produced. The temperature for use in the initial phase (when using a higher temperature) is generally between 40ºC and 100ºC, preferably between 50 ° C and 80 ° C. The temperature during polymerization course is generally in the range of 30 ° C to 80 ° C. The optimal conditions can be determined quickly through routine experimentation.

Actinic radiation can be used, instead of free radical initiators, to initiate polymerization. When actinic radiation, such as UV, is used to initiate polymerization, lower temperatures can be used from approximately 0 ° C to ambient.

The aqueous emulsion polymerization of perfluorovinyl ether can be carried out continuously in which, for example, a previous emulsion of the perfluorovinyl ether monomers, water, emulsifiers fluorochemicals, buffers and initiators to a stirred reactor in optimal pressure and temperature conditions while the resulting dispersion or suspension is continuously removed. A alternative technique is batch polymerization or semi-continuous (semi-continuous) feeding a previous emulsion of the components to a stirred reactor and allowing them to react to a set temperature for a specified duration of time until a desired amount of polymer is formed.

In the second stage of polymerization, the dispersion of the poly (perfluorovinyl ether) is provided with additional fluoromonomers in a continuous or discontinuous mode.

The polymerization can be carried out in a usual or conventional container used for polymerization in emulsion, but usually a pressure vessel is required for the second phase, in which fluorinated monomers are loaded soda

For radical polymerization free, you can make use of any suitable initiator or any suitable initiator system, for example, persulfate of ammonium (APS) or redox systems, such as APS / bisulfite, potassium permanganate or actinic radiation such as UV light. Whether use oil soluble initiators in the polymerization, they generally prefer that these be mixed with the aqueous emulsion of the perfluorovinyl ether monomer. For the purposes of this invention, oil soluble initiators are those that do not they have water solubility, or just insufficient. Examples of water soluble initiators are substituted dibenzoyl peroxides and cumene hydroperoxides, in particular peroxide of bisperfluoropropionyl. For the first stage of polymerization, persulfates are preferred.

Useful water soluble thermal initiators in the present invention are initiators that, with exposure to heat, generate free radicals that initiate the polymerization of monomers comprising the emulsion drops. The initiators Suitable water soluble thermal include, but are not limited to those selected from the group consisting of potassium persulfate, ammonium persulfate, sodium persulfate, and mixtures thereof; and oxidation-reduction initiators such as the reaction product of the aforementioned persulfates and reducing agents such as those selected from the group that It consists of sodium metabisulfite and sodium bisulfite. He Preferred water soluble thermal initiator is ammonium persulfate. Preferably, most of the thermal initiators soluble in water are used at temperatures from about 50 ° C to approximately 70 ° C, while type initiators oxidation-reduction are preferably used at temperatures from about 25 ° C to about 50 ° C Water soluble thermal initiators comprise from about 0.01 to about 2 percent in weight, preferably from about 0.1 to about a 2 percent by weight based on the total weight of monomers in the emulsion.

The amount of oxidizing agent added in the initial charge is usually between 10 and 10,000 ppm. The amount of reducing agent in the initial charge is usually also between 10 and 10,000 ppm. At least one additional charge of oxidizing agent and reducing agent is added to the polymerization system in the course of polymerization. The)
Additional addition (s) may be performed discontinuously or additional addition may be continuous.

The resulting fluoropolymer particles can be used as a dispersion per se . The particles can also be isolated from the aqueous medium by filtration, coagulation, spray drying, extraction with an organic solvent or other techniques such as those known in the art.

The polymerization systems may comprise auxiliary agents, such as buffers and, if desired, trainers of complexes or chain transfer agents.

Fluorochemical compositions

The fluorochemical composition comprises a aqueous fluoropolymer dispersion (whether particles of perfluorovinyl ether homopolymer or bicomponent particles). Generally, the amount of fluoropolymer contained in the Treatment composition is between 0.01 and 4% by weight, preferably between 0.05 and 3% by weight based on weight Total fluorochemical composition. Can also be used higher amounts of fluoropolymer of more than 4% by weight, per example of up to 10% by weight, particularly if the uptake of The fluorochemical composition by the substrate is low. Usually, The fluorochemical treatment composition will be prepared by diluting a more concentrated fluorochemical composition to the desired level of fluoropolymer in the treatment composition. The composition concentrated fluorochemistry may contain the fluoropolymer in a amount of up to 70% by weight, usually between 10% in weight and 50% by weight.

\hbox{200
nm.}

When the fluorochemical composition is in the form of a dispersion in water, the average volume particle size of the fluoropolymer particles is generally not greater than 300 nm, preferably between 50 and

 \ hbox {200
nm.} 

The dispersion can be further stabilized using non-fluorinated surfactants, such as surfactants of nonionic polyoxyalkylene, in particular polyoxyethylene, non-fluorinated anionic surfactants, non-fluorinated surfactants cationic and non-fluorinated zwitterionic surfactants. Examples Specific non-fluorinated surfactants that can be used are non-ionic types such as Emulsogen EPN 207 (Clariant) and Tween 80 (ICI), anionic types such as lauryl sulfate and sodium dodecylbenzenesulfonate, cationic types such as Arquad T-50 (Akzo), Ethoquad 18-25 (Akzo) or amphoteric types such as lauryl-aminoxide and cocamido-propylbetaine. The non-fluorinated surfactant it is preferably present in an amount of about 1 to approximately 25 parts by weight, preferably of about 2 to about 10 parts by weight, based on 100 parts by weight of the fluorochemical composition.

Alternatively, a solution or dispersion of fluoropolymers in an organic solvent such as Fluorochemical treatment composition. Organic solvents Suitable include alcohols such as isopropanol, methoxypropanol and t-butanol, ketones such as isobutyl methyl ketone and methyl ethyl ketone, ethers such as isopropyl ether, esters such as ethyl acetate, butyl acetate or acetate methoxypropanol or (partially) fluorinated solvents such as HCFC-141b, HFC-134a, HFE-7100, HFE-7200 or perfluoroketones HFE-7100, HFE-7200 and perfluoroketones are commercially available from 3M Company, St. Paul, MN.

The fluorochemical composition may contain additional additives such as buffering agents, agents to confer fire resistant or antistatic properties, fungicidal agents, optical bleaching agents, agents sequestrants, mineral salts and swelling agents for Promote penetration It is particularly preferred to include one or more auxiliary components other than fluoropolymer and that can further improve the oil repellent properties and / or to the water of a fibrous substrate treated with the composition fluorochemical or that can improve the elimination properties of dirt / stains of a fibrous substrate treated with the composition fluorochemistry Preferably, the auxiliary components that they can improve the durability of repellency properties and / or dirt / stain removal properties.

Auxiliary components are generally non-fluorinated organic compounds and are also called Extenders later in this document. Extenders suitable that can improve oil repellent properties and / or water include, for example, blocked isocyanates that include aromatic and aliphatic blocked isocyanates, aliphatic polyisoacyanates and aromatic or aliphatic carbodiimides which include aromatic or aliphatic polycarbodiimides. Components auxiliaries that can enhance the elimination properties of dirt / stains are generally non-fluorinated organic compounds such as, for example, blocked isocyanate compounds that they include a polyoxyalkylene group, in particular a group polyoxyethylene The auxiliary components that can usually improve the durability of repellency properties or dirt / stain removal properties include compounds non-fluorinated organics that have one or more groups (or a precursor thereof) that can react with the surface of the substrate fibrous. Examples thereof include compounds that have isocyanate groups or blocked isocyanates.

Method of treatment of fibrous substrates

In order to perform the treatment of fibrous substrate, the fibrous substrate is contacted with the fluoropolymer dispersion of the invention. For example, him substrate can be immersed in the treatment dispersion fluorochemistry The treated substrate can then be run through a foulard / impregnating roller to eliminate the Fluorochemical composition in excess and dry. The treated substrate it can be dried at room temperature leaving it in the air or it can alternatively or additionally undergo a heat treatment, for example, in an oven. This heat treatment is carried out normally at temperatures between about 50 ° C and approximately 190 ° C, depending on the system or method of particular application used. In general, a temperature of about 120 ° C to 170 ° C, in particular of approximately 150 ° C to approximately 170 ° C over a period of approximately 20 seconds to 10 minutes, preferably 3 to 5 minutes Alternatively, the chemical composition can be applied. spraying the composition on the fibrous substrate.

The amount of treatment composition applied to the fibrous substrate is chosen so that a sufficiently high level of the desired properties to the substrate surface without substantially affecting the appearance and touch of the treated substrate. Such amount is normally such that the resulting amount of fluoropolymer on the fibrous substrate treated will be between 0.05% and 3% by weight based on the weight of the fibrous substrate. The amount that is sufficient to confer the desired properties can be determined empirically and can Increase as necessary or desired.

Fibrous substrates that can be treated with the fluorochemical composition include in particular a material textile. The fibrous substrate can be based on synthetic fibers, for example polyester, polyamide or polyacrylate fibers or fibers natural, for example cellulose fibers, as well as mixtures of same. The fibrous substrate can be a woven substrate as well as one non woven.

The invention will be further illustrated with reference to the following examples without the intention of limiting the invention to them. All parts and percentages are by weight at Unless stated otherwise.

Examples Formulation and treatment procedure

\hbox{al
aceite.}

Treatment baths were formulated containing a defined amount of the fluoropolymer treatment agent. The treatments were applied to the test substrates by impregnation with foulard to provide a concentration as indicated in the examples (based on the weight of the fabric and indicated as SOF ("solids on fabric"). dried and cured at a temperature of 300ºF for ten minutes.The substrate used for the evaluation of the treatments of this invention was 100% cotton US-3: cotton available from Test Fa-
Brics, USA. After heat curing, the substrates were tested to determine their repellency properties

 \ hbox {al
oil.} 

Test method for oil repellency (OR, `` oil repellency '')

Oil repellency of a substrate was measured by the usual test method No. 118.1997 of the Association American of Textile Chemists and Colorists (AATCC), proves that based on the resistance of a substrate treated to penetration by oils of variable surface tensions after contact during 30 seconds. To oil resistant treated substrates Kaydol® mineral (the least penetrating of test oils) is gave them a rating of 1, while the substrates n-heptane resistant treaties (the liquid from more penetrating test, of lower surface tension) were given a classification of 8. Other intermediate values were determined through the use of other pure oils or mixtures of oils, such As shown in the following table. A "-" sign after a value indicates the subjective determination by the person giving the classification of an intermediate value between two values (ie 4- indicates a value between 3 and 4).

Test liquids usual

2

GLOSSARY TABLE

3

Example 1 Preparation of homopolymer dispersion of PPVE-2

FLUOROLINK (registered trademark) C dissolved (3.3 g) and potassium hydroxide (0.186 g) in deionized water (90.0 g). To this solution, NAFION (registered trademark) was added SE10172 (0.0175 g) and PPVE-2 (50.0 g); mix resulting aqueous was sonicated for 60 seconds using a Branson 450 sonicator (available from VWR Scientific, Bridgeport, NJ) to produce a thick emulsion. Then, the resulting thick emulsion with a Gaulin 15MR homogenizer (available from APV, St. Paul, MN) at 8800 psi (60.67 MPa) with 3 passes to produce an emulsion with an average droplet size of 144 nm. Be transferred the resulting fine emulsion to a bottom flask 250 ml round 3 mouths, equipped with a top stirrer and An electric blanket A deionized water solution was added (10.0 g), sodium bicarbonate (NaHCO3; 0.2 g) and persulfate ammonium (0.2 g) to the stirred mixture. Then the temperature rose of the mixture and kept at 60 ° C for 20 hours under cover of nitrogen After cooling to room temperature, determined that the homopolymer dispersion performance consequent (characterized using NMR; 29.1% solids) was 97.9%, with an average particle size of 62 nm, measured in the Horiba LA-910 analyzer (Horiba Instruments, Inc, Irvine, CA). The conversion of monomer into homopolymer was of 82%

Examples 2-4 were prepared essentially according to the procedure for example 1, with the except that the conditions and materials were used specified in table 1. The% solids, the average particle size and conversion to homopolymer resulting for examples 2-4, in the table one.

Comparative example C1

Comparative example C1 was prepared essentially according to example 1 with the exception that it is not previously emulsified the resulting aqueous mixture and that the reaction duration was 24 hours instead of 20 hours.

TABLE 1

5

Example 5

Example 5 was prepared essentially according to the procedure used in example 1 with the exception that replaced FLUOROLINK (registered trademark) C with PBS, and the reaction was Run at 71 ° C for 20 hours. The homopolymer dispersion had an average particle size of 230 nm with a conversion of 58%

Example 6

Example 6 was prepared essentially according to the procedure used in example 5 with the exception that omitted the addition of NAFION? SE10172. The dispersion of homopolymer had an average particle size of 157 nm with a 24% conversion.

Example 7

Example 7 was prepared essentially according to the procedure used in example 1 with the exception that replaced PPVE-2 with PPVE-1. The homopolymer dispersion had an average particle size of 63 nm with a conversion of 48%.

Example 8

To deionized water (335.5 g), NAFION was added SE10172 (2.38 g) followed by PPVE-2 (72.0). Be homogenize the resulting mixture using a homogenizer Gaulin 15MR (available from APV, St. Paul, MN) at 8800 psi (60.67 MPa) for 3 passes, producing an emulsion that had a medium size drop of 231 nm. An aliquot of this emulsion (341.6 g) is added a solution of deionized water (20.0 g) and persulfate of ammonium (1.0 g); the resulting mixture was stirred for several minutes, then loaded under vacuum in a 500 high pressure reactor ml equipped with a stirrer, electric blanket, thermocouple, indicator pressure and gas supply valve. After purging twice with nitrogen and expel it, the agitator was set at 800 rpm and the temperature of the mixture at 71 ° C and was maintained for 6 hours.

After 6 hours, a gas mixture was introduced 61% by weight / 39% by weight of VDF / HFP in the reactor at 150 psi (1034 kPa). The total gas feed time in the 500 ml reactor It took 3.42 hours. After the gas supply is complete, it allowed the reactor contents to react further for 2.5 hours The pressure in this period of time decreased from 150 psi (1034 kPa) to approximately 20 psi (138 kPa). He latex with 27.0% solids turned out to have an average size of 112 nm particle.

Example 9

The procedure for example 9 is essentially the same as in example 8, with the exception that the polymerization of the first phase of PPVE-2 emulsion for 3 hours instead of 6 hours, and the average particle size resulting from the latex was 82 nm (26.8% solids).

Example 10

The procedure for example 10 is essentially the same as in example 8, with the exception that the polymerization of the first phase of PPVE-2 emulsion for 0.8 hours instead of 6 hours, and the average particle size resulting from the latex was 127 nm (26.9% solids).

Comparative example C2

The procedure for comparative example C2 is essentially the same as in example 8, with the exception of that the PPVE-2 emulsion charge was followed immediately by the introduction of the VDF / HFP gas mixture, instead of allowing a reaction time of 6 hours. The size particle medium resulting from the latex was 115 nm (27.7% of solids).

TABLE 2 Oil repellency values for the examples 8-10 and comparative example C2 with concentrations cotton variables

6

Claims (16)

1. Bicomponent fluoropolymer dispersion that comprises a homopolymer of poly (perfluorovinyl ether) and a second fluoropolymer. 2. Dispersion according to claim 1, in the that said poly (perfluorovinyl ether) homopolymer comprises polymerized units of monomers of the formula: --- CF_ {2} ---

 \ delm {C} {\ delm {\ para} {R f}} 

F --- in which R_ {f} represents a perfluorinated organic group having a chain length of at minus 2 atoms and that has at least one carbon atom and one atom from oxygen. 3. Dispersion according to claim 1, in the that the group R_ {f} is of the formula: -O (R 1 {} f O) n (R 2 {} f O) m R 3 {f} wherein R 1 f, R 2 f each independently represents a group linear or branched perfluoroalkylene having 1 to 6 atoms of carbon, R 3 f represents a linear perfluoroalkyl group, branched or cyclic having 1 to 6 carbon atoms and n and m each independently represents an integer from 0 to 10. 4. Dispersion according to claim 1, in the that said second fluoropolymer comprises monomer units interpolymerized selected from the tetrafluoroethylene group, vinylidene fluoride, hexafluoropropene, chlorotrifluoroethylene, 2-chloropentafluoropropene, 1-hydropentafluoropropene, dichlorodifluoroethylene, trifluoroethylene, perfluorovinyl ethers, 1,1-chlorofluoroethylene and trichlorethylene. 5. Dispersion according to claim 1, in the that said second fluoropolymer comprises at least one non-monomer fluorinated selected from ethylene and propylene. 6. Dispersion according to claim 1, in the that said fluoropolymer comprises particles having a size 50 to 200 nanometers average. 7. Method of preparing a dispersion of bicomponent fluoropolymer according to any of the claims 1 to 6, which includes the steps of: a) previously emulsify an aqueous mixture of a perfluorovinyl ether monomer in the presence of an emulsifier fluorochemical up to an average emulsion drop size of one micron or less, and b) polymerizing said perfluorovinyl ether in presence of a free radical initiator at a temperature and for a sufficient time to produce particles of poly (perfluorovinyl ether), c) subsequently add at least one comonomer additional fluorinated without additional emulsifier, and d) further polymerize the mixture resulting. 8. Method according to claim 7, wherein said fluoropolymer comprises particles having an average size 50 to 200 nanometers. 9. Method according to claim 7, wherein the degree of conversion of said polymerization into said first polymerization stage is at least 1 percent. 10. Method according to claim 7, wherein the amount of said poly (perfluorovinyl ether) in said Bicomponent particle is from 1 to 75% by weight. 11. Method according to claim 7, wherein said emulsifier is selected from

to)

is a salt of perfluoroalkyl carboxylic acids and linear or branched sulfonic having 4 to 11 carbon atoms in the perfluoroalkyl chain;

b)

perfluoropolymers comprising repeating units that can be derived from a monomer of the formula:

8 in which s is 0, 1 or 2, and t is a integer from 2 to 4, and G is a remainder that contains one or more nonionic, anionic or cationic hydrophilic groups; Y

C)

R_ {a} -O- (CF 2 O) k (CF 2 CF 2 O) p (CF (CF 3) CF 2 O ) q -Q1 -COOM or

MOOC-Q 1 -O- (CF 2 O) k (CF 2 CF 2 O) p (CF (CF 3) CF 2 O) q -Q2 -COOZ

in which k, p and q each represent a value from 0 to 15 and the sum of k, p and q being such that the weight Average molecular number is at least 200 g / mol, R f represents a perfluoroalkyl group of 2 to 4 carbon atoms, M and Z each independently represent hydrogen or a cation, and Q 1 and Q 2 each independently represents -CF 2 - or -CF (CF 3) -. 12. Method according to claim 7, wherein said fluorinated comonomers comprise a fluoromonomer ethylenically unsaturated containing at least one substituent of fluorine atom in a double bond carbon atom, and substituted additionally with a halogen atom, hydrogen or a radical lower fluoroalkyl. 13. Method according to claim 7, wherein said second polymerization step further comprises at least one non-fluorinated monomer selected from ethylene and propylene. 14. Method according to claim 7, wherein said initiator comprises a water soluble initiator. 15. Fluorochemical composition comprising the fluoropolymer dispersion according to any of the claims 1 to 6, and one or more auxiliary components that they can further improve the oil and / or water repellency of a fibrous substrate treated with the fluorochemical composition or a auxiliary component that can provide properties of Improved dirt / stain removal to the fibrous substrate. 16. Method for treating a fibrous substrate that comprises contacting the fibrous substrate with a composition fluorochemistry according to claim 15.